package summer.tree;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

public class Solution226 {
    public TreeNode invertTree(TreeNode root) {
        if (root == null) return null;
        TreeNode left = invertTree(root.left);
        root.left = invertTree(root.right);
        root.right = left;
        return root;
    }
}
